Semiconductor device, method of manufacturing the same, circuit board, and electronic instrument

ABSTRACT

A semiconductor substrate has an integrated circuit, an interconnect electrically connected to the inside of the semiconductor substrate, and an electrode formed on the interconnect. A plurality of resin layers are separately formed on the semiconductor substrate so that part of the semiconductor substrate is exposed. A redistribution interconnect is electrically connected to the electrode. An external terminal is formed on the redistribution interconnect and supported by the resin layers.

CROSS-REFERENCE TO RELATED APPLICATIONS

This is a Divisional of application Ser. No. 10/637,615, filed Aug. 11, 2003, which claims priority to Japanese Patent Application No. 2002-240777 filed on Aug. 21, 2002, and Japanese Patent Application No. 2003-284995 filed on Aug. 1, 2003, all are hereby incorporated by reference in their entirety.

BACKGROUND OF THE INVENTION

The present invention relates to a semiconductor device, a method of manufacturing the same, a circuit board, and an electronic instrument.

FIG. 15 is a plan view schematically showing a configureation of a convention chip size package. FIG. 16 is a cross-sectional view of the chip size package shown in FIG. 15 taken along the line XVI-XVI. An interconnect layer 122 connected with an active region is formed on a semiconductor device 121, and pads 123 are formed on the interconnect layer 122. A stress relief layer 124 is formed on the active region of the semiconductor device 121 so that the pads 123 are exposed. A redistribution interconnect 125 is formed from the top of the pad 123 so as to extend onto the stress relief layer 124. A solder resist film 126 is formed on the redistribution interconnect 125. An opening 127 which exposes a part of the redistribution interconnect 125 on the stress relief layer 124 is formed in the solder resist film 126. A solder ball 128 is formed on the redistribution interconnect 125 through the opening 127. The stress relief layer 124 and the solder resist film 126 are formed of a resin.

Therefore, since the resin layer is formed over a wide area of the semiconductor device 121, it is difficult to prevent warping of the semiconductor device 121 which occurs due to internal stress of the resin layer.

BRIEF SUMMARY OF THE INVENTION

According to a first aspect of the present invention, there is provided a semiconductor device comprising:

-   -   a semiconductor substrate having an integrated circuit, an         interconnect electrically connected to the inside of the         semiconductor substrate, and an electrode formed on the         interconnect;     -   a plurality of resin layers separately formed on the         semiconductor substrate so that part of the semiconductor         substrate is exposed;     -   a redistribution interconnect electrically connected to the         electrode; and     -   an external terminal formed on the redistribution interconnect         and supported by the resin layers.

According to a second aspect of the present invention, there is provided a semiconductor device comprising:

-   -   a semiconductor substrate having an integrated circuit formed in         the semiconductor substrate, an interconnect electrically         connected to the inside of the semiconductor substrate, and an         electrode formed on the interconnect;     -   a resin layer formed on the semiconductor substrate and having a         penetrating hole so that part of the semiconductor substrate is         exposed;     -   a redistribution interconnect electrically connected to the         electrode; and

an external terminal formed on the redistribution interconnect and supported by the resin layer.

According to a third aspect of the present invention, there is provided a semiconductor device comprising:

-   -   an interposer substrate on which a semiconductor chip is         surface-mounted;     -   an interconnect layer formed on a back surface of the interposer         substrate;     -   protective layers separately disposed on the interconnect layer;     -   a solder ball connected to the interconnect layer through the         protective layer; and     -   a through-hole formed in the interposer substrate and connecting         the semiconductor chip with the interconnect layer.

According to a fourth aspect of the present invention, there is provided a circuit board on which is mounted the above-described semiconductor device.

According to a fifth aspect of the present invention, there is provided an electronic instrument comprising the above-described semiconductor device.

According to a sixth aspect of the present invention, there is provided a method of manufacturing a semiconductor device comprising:

-   -   forming a plurality of resin layers separated from each other on         a semiconductor substrate so that part of the semiconductor         substrate is exposed, the semiconductor substrate having an         integrated circuit, an interconnect electrically connected to         the inside of the semiconductor substrate, and an electrode         formed on the interconnect;     -   forming a redistribution interconnect electrically connected to         the electrode; and     -   forming an external terminal on the redistribution interconnect         to be supported by the resin layers.

According to a seventh aspect of the present invention, there is provided a method of manufacturing a semiconductor device comprising:

-   -   forming a resin layer on a semiconductor substrate which has an         integrated circuit, an interconnect electrically connected to         the inside of the semiconductor substrate, and an electrode         formed on the interconnect, the resin layer including a         penetrating hole which exposes part of the semiconductor         substrate;     -   forming a redistribution interconnect electrically connected to         the electrode; and     -   forming an external terminal on the redistribution interconnect         to be supported by the resin layer.

According to an eighth aspect of the present invention, there is provided a method of manufacturing a semiconductor device comprising:

-   -   forming an interconnect layer on both surfaces of an interposer         substrate, the interconnect layers being connected to each other         by a through-hole;     -   forming a protective layer on one of the interconnect layers         provided on a back surface of the interposer substrate;     -   dividing the protective layer by patterning to form an opening         which exposes part of the one of the interconnect layers;     -   forming a solder ball connected to the one of the interconnect         layers through the opening; and     -   mounting a semiconductor chip on the interposer substrate.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

FIG. 1 is a plan view schematically showing a semiconductor device according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional view of the semiconductor device taken along the line the line II-II in FIG. 1

FIGS. 3A to 3E are cross-sectional views for illustrating a method of manufacturing a semiconductor device according to the first embodiment of the present invention.

FIG. 4 is a view for illustrating the method of manufacturing a semiconductor device according to the first embodiment of the present invention.

FIG. 5 is a cross-sectional view for illustrating a semiconductor device according to a second embodiment of the present invention.

FIG. 6 is a cross-sectional view for illustrating a semiconductor device according to a third embodiment of the present invention.

FIG. 7 is a plan view schematically showing a semiconductor device according to a fourth embodiment of the present invention.

FIG. 8 is a cross-sectional view of the semiconductor device taken along the line VIII-VIII in FIG. 7.

FIG. 9 is a cross-sectional view of the semiconductor device taken along the line IX-IX in FIG. 7.

FIG. 10 is a cross-sectional view of a semiconductor device according to a fifth embodiment of the present invention.

FIG. 11 is a bottom view of the semiconductor device shown in FIG. 10.

FIG. 12 shows a circuit board on which is mounted a semiconductor device according to one embodiment of the present invention.

FIG. 13 shows an electronic instrument having a semiconductor device according to one embodiment of the present invention.

FIG. 14 shows another electronic instrument having a semiconductor device according to one embodiment of the present invention.

FIG. 15 is a plan view schematically showing the configuration of a conventional chip size package.

FIG. 16 is a cross-sectional view of the chip size package taken along the line XVI-XVI in FIG. 15.

DETAILED DESCRIPTION OF THE EMBODIMENTS

An objective of embodiments of the present invention is to disperse stress of the resin layer.

(1) According to one embodiment of the present invention, there is provided a semiconductor device comprising:

-   -   a semiconductor substrate having an integrated circuit, an         interconnect electrically connected to the inside of the         semiconductor substrate, and an electrode formed on the         interconnect;     -   a plurality of resin layers separately formed on the         semiconductor substrate so that part of the semiconductor         substrate is exposed;     -   a redistribution interconnect electrically connected to the         electrode; and     -   an external terminal formed on the redistribution interconnect         and supported by the resin layers. According to this         semiconductor device, since the resin layers are separately         formed, internal stress is dispersed in comparison with the case         where the resin layer is integrally formed. Since force applied         to the semiconductor substrate is dispersed, warping of the         semiconductor substrate can be reduced.

(2) In this semiconductor device, a penetrating hole may be formed in at least one of the resin layers.

(3) According to one embodiment of the present invention, there is provided a semiconductor device comprising:

-   -   a semiconductor substrate having an integrated circuit formed in         the semiconductor substrate, an interconnect electrically         connected to the inside of the semiconductor substrate, and an         electrode formed on the interconnect;     -   a resin layer formed on the semiconductor substrate and having a         penetrating hole so that part of the semiconductor substrate is         exposed;     -   a redistribution interconnect electrically connected to the         electrode; and     -   an external terminal formed on the redistribution interconnect         and supported by the resin layer. According to this         semiconductor device, since the penetrating hole is formed in         the resin layer, internal stress is dispersed in comparison with         the case where the penetrating hole is not formed. Since force         applied to the semiconductor substrate is dispersed, warping of         the semiconductor substrate can be reduced.

(4) In this semiconductor device, the penetrating hole may be a slot.

(5) In this semiconductor device, the semiconductor substrate may be in the shape of a rectangle; and the slot may be formed along a diagonal of the rectangle.

(6) In this semiconductor device, an element may be formed in a portion of the semiconductor substrate exposed from the resin layers.

(7) In this semiconductor device, the redistribution interconnect may be formed to extend onto the resin layers.

(8) In this semiconductor device, the redistribution interconnect may be formed to pass under the resin layers; a conductive post may be formed on the redistribution interconnect to pass through the resin layers; and the external terminal may be formed on the conductive post.

(9) This semiconductor device may further comprise a second resin layer formed on the resin layers avoiding a region between the adjacent resin layers.

(10) According to one embodiment of the present invention, there is provided a semiconductor device comprising:

-   -   an interposer substrate on which a semiconductor chip is         surface-mounted;     -   an interconnect layer formed on a back surface of the interposer         substrate;     -   protective layers separately disposed on the interconnect layer;     -   a solder ball connected to the interconnect layer through the         protective layer; and     -   a through-hole formed in the interposer substrate and connecting         the semiconductor chip with the interconnect layer. According to         this semiconductor device, the semiconductor chip can be sealed         with a mold resin and the arrangement density of the solder         balls can be increased. Moreover, the stress applied to the         interconnect layer can be reduced. Therefore, reliability of         secondary mounting can be improved and the mounting density can         be increased.

(11) According to one embodiment of the present invention, there is provided a circuit board on which is mounted the above semiconductor device.

(12) According to one embodiment of the present invention, there is provided an electronic instrument comprising the above semiconductor device.

(13) According to one embodiment of the present invention, there is provided a method of manufacturing a semiconductor device comprising:

-   -   forming a plurality of resin layers separated from each other on         a semiconductor substrate so that part of the semiconductor         substrate is exposed, the semiconductor substrate having an         integrated circuit, an interconnect electrically connected to         the inside of the semiconductor substrate, and an electrode         formed on the interconnect;     -   forming a redistribution interconnect electrically connected to         the electrode; and     -   forming an external terminal on the redistribution interconnect         to be supported by the resin layers. According to this method of         manufacturing a semiconductor device, since the resin layers are         separately formed, internal stress is dispersed in comparison         with the case where the resin layers are integrally formed.         Since the force applied to the semiconductor substrate is         dispersed, warping of the semiconductor substrate can be         reduced.

(14) According to one embodiment of the present invention, there is provided a method of manufacturing a semiconductor device comprising:

-   -   forming a resin layer on a semiconductor substrate which has an         integrated circuit, an interconnect electrically connected to         the inside of the semiconductor substrate, and an electrode         formed on the interconnect, the resin layer including a         penetrating hole which exposes part of the semiconductor         substrate;     -   forming a redistribution interconnect electrically connected to         the electrode; and     -   forming an external terminal on the redistribution interconnect         to be supported by the resin layer. According to this method of         manufacturing a semiconductor device, since the resin layer is         formed to include the penetrating hole, internal stress is         dispersed in comparison with the case where the penetrating hole         is not formed. Since the force applied to the semiconductor         substrate is dispersed, warping of the semiconductor substrate         can be reduced.

(15) A method of manufacturing a semiconductor device according to yet another embodiment of the present invention comprises:

-   -   forming an interconnect layer on both surfaces of an interposer         substrate, the interconnect layers being connected to each other         by a through-hole;     -   forming a protective layer on one of the interconnect layers         provided on a back surface of the interposer substrate;     -   dividing the protective layer by patterning to form an opening         which exposes part of the one of the interconnect layers;     -   forming a solder ball connected to the one of the interconnect         layers through the opening; and     -   mounting a semiconductor chip on the interposer substrate.         According to this method of manufacturing a semiconductor         device, the semiconductor chip can be sealed with a mold resin         and the arrangement density of the solder balls can be         increased. Moreover, the stress applied to the interconnect         layer can be reduced without increasing the number of         manufacturing steps. This enables reliability of secondary         mounting to be improved and the mounting density to be increased         while preventing an increase in cost.

The embodiments of the present invention are described below with reference to the drawings.

First Embodiment

FIG. 1 is a plan view showing a semiconductor device according to a first embodiment of the present invention. FIG. 2 is a cross-sectional view of the semiconductor device taken along the line II-II in FIG. 1. The semiconductor device includes a semiconductor substrate 10. The semiconductor substrate 10 shown in FIG. 1 is a semiconductor chip. However, a semiconductor wafer may also be used. An integrated circuit 12 is formed in the semiconductor substrate 10. One integrated circuit 12 is formed in a semiconductor chip, and a plurality of integrated circuits 12 are formed in a semiconductor wafer. A region in which the integrated circuit 12 is formed may be referred to as an active region. The integrated circuit 12 may include an element 14 such as a fuse, transistor, or sensor (optical element (light receiving element or light emitting element), for example).

The semiconductor substrate 10 includes a plurality of interconnects (or interconnect layer) 16 electrically connected with the inside of the semiconductor substrate 10. The interconnects 16 include an interconnect electrically connected with the integrated circuit 12 (or active region). The interconnects 16 may include an interconnect connected with the inside of the semiconductor substrate 10 without being electrically connected with the integrated circuit 12. An electrode (pad) 18 is formed on the interconnect 16.

The semiconductor substrate 10 may include a passivation film 20. The passivation film 20 may be a resin film, a silicon oxide film, or a silicon nitride film. The passivation film 20 may be transparent such as a silicon oxide film, or may be opaque. The passivation film 20 may be formed to avoid a part (center, for example) of the electrode 18. The passivation film 20 covers the interconnects 16. The passivation film 20 may cover the entire integrated circuit 12 (or active region). If the passivation film 20 is transparent, the passivation film 20 may cover the element 14 even if the element 14 is an optical element (see FIG. 3A).

A plurality of resin layers 30 are separately formed on the semiconductor substrate 10. The resin layer 30 is formed so that a part of the semiconductor substrate 10 (part of the passivation film 20, for example) is exposed. The resin layer 30 is an electrical insulating layer. The resin layer 30 does not contain conductive particles. The resin layer 30 may have a stress relief function. The resin layer 30 may be formed of a polyimide resin, silicone-modified polyimide resin, epoxy resin, silicone-modified epoxy resin, benzocyclobutene (BCB), polybenzoxazole (PBO), or the like. The resin layer 30 is formed of a material having a light shielding property. The resin layer 30 is formed to avoid the top of the electrode 18. At least a part of the resin layer 30 may be formed on the integrated circuit 12 (or active region). The resin layer 30 may be formed to avoid the top of the element 14. In the case where the element 14 is located in an area 22 exposed from the resin layer 30, even if the resin layer 30 is opaque, light enters the element 14 if the passivation film 20 is transparent. If the resin layer 30 is formed to avoid the top of the element 14, the element 14 is not influenced by internal stress of the resin layer 30.

The semiconductor device includes a redistribution interconnect 32 electrically connected with the electrode 18. The redistribution interconnect 32 is formed so that a part of the redistribution interconnect 32 overlaps the electrode 18. The redistribution interconnect 32 is formed to extend onto the resin layer 30 (upper surface of the resin layer 30, for example). The redistribution interconnect 32 may pass on the passivation film 20. The redistribution interconnect 32 may be formed of a three-layer structure consisting of a TiW sputter interconnect layer, a Cu sputter interconnect layer, and a Cu plating interconnect layer, for example.

An external terminal (solder ball, for example) 34 is formed on the redistribution interconnect 32. The external terminal 34 may be formed of soft solder or hard solder. As the soft solder, solder containing no lead (hereinafter called lead-free solder) may be used. As the lead-free solder, a tin-silver (Sn—Ag) alloy, tin-bismuth (Sn—Bi) alloy, tin-zinc (Sn—Zn) alloy, or tin-copper (Sn—Cu) alloy may be used. At least one of silver, bismuth, zinc, and copper may be added to these alloys. The external terminal 34 is formed on the resin layer 30 and is supported by the resin layer 30. Therefore, a part of the external force applied to the external terminal 34 is absorbed by the resin layer 30.

The semiconductor device may include a plurality of second resin layers (protective layers such as a solder resist) 36. The second resin layer 36 is formed on the resin layer 30. The second resin layers 36 are separately disposed corresponding to the resin layers (stress relief layers) 30. The second resin layers 36 are formed to avoid the region between the adjacent resin layers (first resin layers) 30. The second resin layer 36 may be formed to avoid the entire area 22 of the semiconductor substrate 10 exposed from the resin layer 30, or may cover the edge of the area 22. The second resin layer 36 is formed to avoid the top of the element 14.

The second resin layer 36 is formed to cover the redistribution interconnect 32 while avoiding an area of the redistribution interconnect 32 in which the external terminal 34 is formed (land, for example). An opening which exposes the redistribution interconnect 32 is formed in the second resin layer 36 on the resin layer 30. The external terminal 34 is connected with the redistribution interconnect 32 through the opening formed in the second resin layer 36. The second resin layer 36 is in contact with at least the base of the external terminal 34. The second resin layer 36 may cover the electrode 18.

According to this embodiment, since the resin layers 30 are separately formed, internal stress is dispersed in comparison with the case where the resin layer 30 is integrally formed. Therefore, since force applied to the semiconductor substrate 10 is dispersed, warping of the semiconductor substrate 10 can be reduced.

According to this embodiment, the amount of expansion and contraction of the resin layer 30 formed on the interconnects 16 can be reduced, and the amount of expansion and contraction of the second resin layer 36 formed on the redistribution interconnects 32 can be reduced. Therefore, external force applied to the interconnects 16 and the redistribution interconnects 32 can be reduced, whereby the external terminals 34 can be formed on the semiconductor substrate 10 while reducing strain which occurs in the interconnects 16 and the redistribution interconnects 32. This enables reliability of secondary mounting to be improved and the mounting density to be increased.

FIGS. 3A to 3E are cross-sectional views for illustrating a method of manufacturing a semiconductor device according to this embodiment. In the following description of the manufacturing method, a semiconductor wafer is used as the semiconductor substrate 10. As shown in FIG. 3A, the element 14 is formed on the semiconductor substrate 10. The integrated circuit 12 is formed in the semiconductor substrate 10. The semiconductor substrate 10 includes the interconnect 16 which is electrically connected with the inside of the semiconductor substrate 10. The electrode 18 is formed on the interconnect 16.

As shown in FIG. 3B, the resin layers 30 are separately formed on the semiconductor substrate 10 (passivation film 20, for example) so that a part of the semiconductor substrate 10 (part of the surface of the passivation film 20, for example) is exposed.

The formation process of the resin layer 30 may include applying a resin precursor (thermosetting resin precursor, for example) to the semiconductor substrate 10, or forming a resin precursor layer by spreading a resin precursor on the semiconductor substrate 10 by spin coating. A continuous or integral resin precursor layer may be formed by using a radiation sensitive resin precursor having a property sensitive to radiation (light (ultraviolet light or visible light), X-rays, or electron beams), and the resin precursor layer may be patterned into a plurality of the resin layers 30. The resin precursor layer is patterned by applying lithography. The resin layers 30 may be formed by printing (screen printing, for example). Each of the resin layers 30 may be formed of either a plurality of layers or a single layer. The resin layer 30 is formed to avoid the top of the electrode 18. The resin layer 30 is formed to avoid the top of the element 14. The resin layer 30 may be formed to avoid a cutting region of the semiconductor substrate 10.

As shown in FIG. 3C, the redistribution interconnect 32 is formed so as to be electrically connected with the electrode 18. The redistribution interconnect 32 is formed to extend onto the resin layer 30. The redistribution interconnect 32 is formed to pass on the electrode 18. The redistribution interconnect 32 may pass on the side surface of the resin layer 30. The redistribution interconnect 32 may be formed to have a land (area wider than the line). The external terminal 34 is formed on the land. The redistribution interconnect 32 may be formed of either a single layer or a plurality of layers. For example, a TiW sputter film and a Cu sputter film are stacked by sputtering, and a plating resist film is then formed. An opening corresponding to the redistribution interconnect 32 is formed in the plating resist film by using photolithographic technology, and a Cu plating interconnect layer is formed by copper electroplating through the opening. The plating resist film is then removed, and a Cu sputter interconnect layer and a TiW sputter interconnect layer are formed by etching the Cu sputter film and the TiW sputter film by using the Cu plating interconnect layer as a mask to form the redistribution interconnect 32.

As shown in FIG. 3D, the second resin layer 36 may be formed on the resin layer 30. The description of the resin layer 30 may be applied to the second resin layer 36. The second resin layer 36 may be a solder resist. The second resin layer 36 is formed to cover the redistribution interconnect 32 excluding a part (center of the land, for example) of the redistribution interconnect 32. The second resin layer 36 is formed to avoid the region between the adjacent resin layers 30. The second resin layer 36 may be formed so that the cutting region of the semiconductor substrate 10 is exposed.

As shown in FIG. 3E, the external terminal 34 is formed on the redistribution interconnect 32 so that the external terminal 34 is supported by the resin layer 30. The external terminal 34 may be formed by applying a conventional method.

A third resin layer (not shown) may optionally be formed on the second resin layer 36. The description of the resin layer 30 may be applied to the third resin layer. The third resin layer is formed to cover an area other than the top of the external terminal 34. This enables stress which occurs due to external force applied to the external terminal 34 to be dispersed. This also enables bonding between the external terminal 34 and the redistribution interconnect 32 to be reinforced. The third resin layer may be formed to cover the entire semiconductor substrate 10 and then patterned. The third resin layer may be formed to cover the external terminal 34 and removed from the top of the external terminal 34. The third resin layer may be patterned by applying lithography. A part of the third resin layer may be removed by using a laser or ashing.

As shown in FIG. 4, the semiconductor substrate 10 may be cut (diced or scribed). If the resin layer 30 and the second resin layer 36 are not formed in the cutting region of the semiconductor substrate 10, clogging of a cutter (or blade) 38 can be prevented since the resin is not cut. The semiconductor device is thus obtained.

Second Embodiment

FIG. 5 is a cross-sectional view for illustrating a semiconductor device according to a second embodiment of the present invention. In this embodiment, a redistribution interconnect 42 is formed to pass under a resin layer 40. The redistribution interconnect 42 is formed on the passivation film 20. A conductive post 44 is formed on the redistribution interconnect 42. The conductive post 44 is formed through the resin layer 40. Specifically, a penetrating hole 46 is formed in the resin layer 40. An external terminal 48 is formed on the conductive post 44. The description in the first embodiment is applied to other configurations and the manufacturing method.

According to this embodiment, since the penetrating hole 46 is formed in the resin layer 40, an effect equal to that in the case where the resin layer 40 is further divided can be obtained, whereby warping of the semiconductor substrate 10 can be further reduced.

Third Embodiment

FIG. 6 is a cross-sectional view for illustrating a semiconductor device according to a third embodiment of the present invention. In this embodiment, a redistribution interconnect 52 is formed to pass under a resin layer 50. The redistribution interconnect 52 is formed on the passivation film 20. A penetrating hole 54 is formed in the resin layer 50. The penetrating hole 54 is formed to overlap a part of the redistribution interconnect 52. Specifically, the resin layer 50 is formed so that a part of the redistribution interconnect 52 is exposed through the penetrating hole 54. An interconnect 56 is formed to extend from the redistribution interconnect 52 in the area exposed from the resin layer 50 to the resin layer 50 through the inner surface of the penetrating hole 54. An external terminal 58 is formed on the interconnect 56. The description in the first embodiment is applied to other configurations and the manufacturing method.

According to this embodiment, since an effect equal to that in the case where the resin layer 50 is further divided can be obtained by forming the penetrating hole 54 in the resin layer 50, warping of the semiconductor substrate 10 can be further reduced.

Fourth Embodiment

FIG. 7 is a plan view showing a semiconductor device according to a fourth embodiment of the present invention. FIG. 8 is a cross-sectional view of the semiconductor device taken along the line VIII-VII in FIG. 7. FIG. 9 is a cross-sectional view of the semiconductor device taken along the line IX-IX in FIG. 7. The semiconductor device includes a semiconductor substrate 60. The semiconductor substrate 60 includes one or more elements 62. The element 62 is a fuse, transistor, sensor (optical element (light receiving element or light emitting element), for example), or the like. The element 62 may be an element which is easily influenced by external force, or an element which emits or receives light. The description of the semiconductor substrate 10 in the first embodiment is applied to the semiconductor substrate 60.

A resin layer 64 is formed on the semiconductor substrate 60. One or more penetrating holes 66 and 68 are formed in the resin layer 64. The penetrating hole 66 is formed so that the element 62 is disposed inside the penetrating hole 66. This prevents the element 62 from being covered with the resin layer 64, whereby the element 62 is not influenced by internal stress of the resin layer 64. Moreover, emission or reception of light by the element 62 is not prevented. The penetrating hole 66 may be formed at the center of the resin layer 64.

The penetrating hole 68 is a slot. The semiconductor substrate 60 is in the shape of a rectangle, and the penetrating hole (slot) 68 is formed along the diagonal of the rectangle. The penetrating hole 68 is formed so as not to cut the resin layer 64. The penetrating hole (slot) 68 is formed to avoid the edge of the resin layer 64. The penetrating hole 68 may be formed to avoid the center of the resin layer 64.

A method of manufacturing the semiconductor device includes forming the resin layer 64 having the penetrating holes 66 and 68 which expose a part of the semiconductor substrate 60 on the semiconductor substrate 60. The description in the first embodiment is applied to other configurations and the manufacturing method. According to this embodiment, since an effect equal to that in the case where the resin layer 64 is divided can be obtained by forming the penetrating holes 66 and 68 in the resin layer 64, warping of the semiconductor substrate 60 can be further reduced.

Fifth Embodiment

FIG. 10 is a cross-sectional view showing a semiconductor device according to a fifth embodiment of the present invention. FIG. 11 is a bottom view of the semiconductor device shown in FIG. 10. In FIG. 10, interconnect layers 72 and 74 are formed on each surface of an interposer substrate 70. The interconnect layers 72 and 74 are connected through a through-hole 76. A semiconductor chip (IC chip, for example) 78 is mounted (surface-mounted, for example) on the surface of the interposer substrate 70. The semiconductor chip 78 is connected with the interconnect layer 72 through a bump 80 and is sealed with a mold resin 82. A protective layer (solder resist film, for example) 84 which protects the interconnect layer 74 is formed on the interconnect layer 74 on the back surface of the interposer substrate 70. The protective layers 84 are separately disposed. An opening 86 which exposes the interconnect layer 74 is formed in the protective layer 84. A solder ball 90 is disposed on the interconnect layer 74 through the opening 86. The solder ball 90 is connected with the interconnect layer 74 through the opening 86 formed in the protective layer 84. This enables the amount of expansion and contraction of the protective layer 84 formed on the interconnect layer 74 to be reduced, whereby force applied to the interconnect layer 74 can be reduced. Therefore, strain which occurs in the interconnect layer 74 can be reduced in a semiconductor device having a ball grid array (BGA) structure, whereby reliability of secondary mounting can be improved and the mounting density can be increased.

In a method of manufacturing the semiconductor device according to this embodiment, the interconnect layers 72 and 74 connected through the through-hole 76 are formed on each surface of the interposer substrate 70. The protective layer 84 is formed on the interconnect layer 74 formed on the back surface of the interposer substrate 70. The protective layer 84 is divided and the opening 86 which exposes the interconnect layer 74 is formed by patterning the protective layer 84. The solder ball 90 is formed so as to be connected with the interconnect layer 74 through the opening 86. The semiconductor chip 78 is mounted on the surface of the interposer substrate 70.

FIG. 12 shows a circuit board 1000 on which the semiconductor device 1 described in the above embodiment is mounted. FIGS. 13 and 14 respectively show a notebook-type personal computer 2000 and a portable telephone 3000 as examples of electronic instruments including the semiconductor device.

The present invention is not limited to the above-described embodiments. Various modifications and variations are possible. For example, the present invention includes configurations essentially the same as the configurations described in the embodiments (for example, configurations having the same function, method, and results, or configurations having the same object and results). The present invention includes configurations in which any unessential part of the configuration described in the embodiments is replaced. The present invention includes configurations having the same effects or achieving the same object as the configurations described in the embodiments. The present invention includes configurations in which conventional technology is added to the configurations described in the embodiments. 

1. A semiconductor device comprising: a semiconductor substrate having an integrated circuit formed in the semiconductor substrate, an interconnect electrically connected to the inside of the semiconductor substrate, and an electrode formed on the interconnect; a resin layer formed on the semiconductor substrate and having a penetrating hole so that part of the semiconductor substrate is exposed; a redistribution interconnect electrically connected to the electrode; and an external terminal formed on the redistribution interconnect and supported by the resin layer.
 2. The semiconductor device as defined in claim 1, wherein the penetrating hole is a slot.
 3. The semiconductor device as defined in claim 2, wherein: the semiconductor substrate is in the shape of a rectangle; and the slot is formed along a diagonal of the rectangle.
 4. The semiconductor device as defined in claim 1, wherein an element is formed in a portion of the semiconductor substrate exposed from the resin layer.
 5. The semiconductor device as defined in claim 1, wherein the redistribution interconnect is formed to extend onto the resin layer.
 6. The semiconductor device as defined in claim 1, wherein: the redistribution interconnect is formed to pass under the resin layer; a conductive post is formed on the redistribution interconnect to pass through the resin layer; and the external terminal is formed on the conductive post.
 7. The semiconductor device as defined in claim 1, further comprising: a second resin layer formed on the resin layer avoiding a region between the adjacent resin layers.
 8. A circuit board on which is mounted the semiconductor device as defined in claim
 1. 9. An electronic instrument comprising the semiconductor device as defined in claim
 1. 10. A method of manufacturing a semiconductor device comprising: forming a resin layer on a semiconductor substrate which has an integrated circuit, an interconnect electrically connected to the inside of the semiconductor substrate, and an electrode formed on the interconnect, the resin layer including a penetrating hole which exposes part of the semiconductor substrate; forming a redistribution interconnect electrically connected to the electrode; and forming an external terminal on the redistribution interconnect to be supported by the resin layer. 